We exited the motorway, and soon turned onto a broad highway that ran parallel to the nearby banks of the Pinheiros. I studied the map and saw we had already covered most of the distance to our destination.

‘Okay,’ said Nadia, glancing sideways at the map on my knees. ‘We’re almost there. Keep your eyes peeled, both of you.’

‘This place we’re going to,’ I asked. ‘Do we know what it looks like?’

Oskar reached into the envelope Casey had given him earlier, and pulled out some grainy-looking photographs before passing them over to me. ‘Aerial drone reconnaissance,’ he explained. ‘See that white building, about two storeys high?’ He leaned forward, reaching between the two front seats to tap at the picture.

I studied the photo, and then the map, comparing them. ‘If I’m reading this right, then Retièn’s labs are just seven or eight blocks from here, straight on ahead.’

‘Slight problem,’ said Nadia, nodding ahead. ‘Look.’

I glanced through the windscreen, and saw that part of a building had collapsed across the street straight ahead of us, blocking the avenue.

‘We’re going to have to take a detour,’ said Nadia, pulling once more to a halt. ‘No way I can get past that. I’ll hang a right, take a route down a side street, then come back onto this road.’

‘I really don’t like this,’ said Oskar quietly.

Nadia’s hands tapped out a staccato rhythm on the wheel. ‘Me neither.’

For a second I thought she was going to turn back. She glanced sideways at me, fixing me with her gaze, and I knew she was trying to make up her mind. Then she started us forwards again, first taking a right into a side street, then a left at the next corner.

Up ahead, at the next intersection, I saw a number of bee-brains milling about in a loose mob like a sleepwalker’s convention. Then I saw they were all carrying stuff out of the gutted shell of a shopping mall on the other side of the intersection. In their hands I saw pieces of broken furniture, desk ornaments, chairs, bricks, and pretty much anything that wasn’t too big or unwieldy to either carry or drag after them. It was like stumbling across a fire sale in the midst of a zombie apocalypse.

‘Oh hell,’ said Nadia.

I had left the window open on my side, to alleviate the tropical heat. A cool breeze swept past us and towards the bee-brains. Almost immediately, a number of the creatures came to a halt, their heads swivelling around to regard us. I closed the window again, afraid they were about to come running at us.

‘Nadia?’ asked Oskar. ‘Why the fuck are they looking at us?’

‘I don’t know.’ She grabbed the map from my lap and studied it closely, her lips pale and bloodless.